12 Week Benchmark Study Guide Organisms Characteristics of Living Things (Biology: the study of living things) Homeostasis – maintaining a balanced internal conditions Organization - Cells Tissue Organs Organ systems Organism (living thing) Growth - gets bigger or adds cells or matures Reproduce - asexual or sexual; making more of one’s species Energy - organisms must make or obtain energy (food) – ‘metabolism’ Cells - all living things are made of cells or at least one cell (unicellular) Respond - responding to stimuli such as temperature, pH, needs such as food,….etc. Viruses - They are NOT alive. They do not meet all of the HOGRECR - Antibiotics do not kill or help a viral infection such as the common cold or influenza. - Viruses are not plants, animals, or bacteria, but they are parasites of the living kingdoms. Protein Capsid - contains the nucleic acid (DNA) Classification Taxonomy - The study of classification! Aristotle– grouped things by where they lived (environment Linnaeus – developed our classification system used now... uses 2 Latin words – Binomial Nomenclature 7 levels of Classification Kingdoms 6 Kingdoms: Archaebacteria, Eubacteria, Protists, Fungi, Plantae, Animalia Phylum Scientific Name -the Genus (capitalized) and Species. Large Class order to family Genus small Species Example : Homo sapiens or Homo sapiens Unicellular Multicellular Eubacteria Archaebacteria Most Protists Autotrophic Plants plant-like Protists Some chlorophyll containing Bacteria Fungi Plants Animals Algae (Protist) Heterotrophic animal-like Protists fungi-like Protists Bacteria Fungi (by absorption) Animals (by ingestion) Producer Consumer Plants algae-like Protists Some chlorophyll containing Bacteria Decomposer animal-like Protists Animals Fungi-like Protists Fungi Bacteria GENETICS Mendelian Genetics and Meiosis/Mitosis Asexual Reproduction Sexual Reproduction Binary Fission – bacteria Cloning – cells Budding – like the hydras Vegetative Propagation - Runners/shoots – like some plants Conjugation of unicellular organism External fertilization – like frogs and fish Internal fertilization – like mammals Alternation of Generations Fungi – going from asexual producing spores to sexual union of specialized cells Moss plants – sporophytes that produce spores to gameteophytes making sperm and egg Mitosis : 1 body (somatic) cell divides to make 2 new cells Diploid (2n) --- Diploid (2n) Interphase: Prophase: Resting (from nuclear division) DNA replicates chromosomes become visible Metaphase: chromosome line-up along the middle Anaphase: Telophase: chrosmosomes begin to separate (pull apart) chromosomes have separated; cell pinches in or develops a cell plate Cytokinesis – when animal cells pinch in dividing the cytoplasm in the last stage of mitosis Meiosis : cell division to create gametes (sex cells: sperm & egg) -diploid (2n) -- haploid (1n) -1 cell divides to make 4 haploid cells *** Crossing over during Prophase I allows more genetic variation!!! Prophase I Metaphase I (crossing over of tetrads) (Homologous Pairs) Prophase II Metaphase II (chromosomes line up single) Anaphase I (homologous pairs separate) Anaphase II (chromatids pull apart) Telophase I (2 haploid cells) Telophase II (4 new gamete haploid cells) When an egg is fertilized by one sperm it becomes a zygote. Zygotes go through Mitosis to grow and develop into a blastula gastrula embryo. fertilization mitosis Karyotype – picture of a person’s homologous chromosomes ex chromosomes: XX – female XY – male This karyotype is of an individual with Down Syndrome or Trisomy 21- resulting from nondisjunction ‘The Father of Genetics’ - Gregor Mendel An Austrian monk that grew garden peas. He observed and recorded the factors for flower color, pea color, and pea texture for several generations. Three conclusions/laws: 1 - Dominant & Recessive traits 2 – Independent Assortment 3 – Segregation of alleles (during gamete formation) Humans have 46 (2n) chromosomes in each somatic cell. - There are 23 Homologous Pairs for each chromosome. - There are 2 sex chromosomes: XX female & XY male. - Somatic cells (body cells) are coded for in the autosomes (22 pairs) Humans have 23 (1n) chromosomes in each gamete. Alleles – different forms of the same gene (eye colors) Tetrads are formed in Meiosis - the Homologous pairs become entangled in a process called synapsis. Crossing over can occur during this time. (Prophase I) (It is the Homologous pair that is pulled apart during Anaphase I) Genotype - the traits (alleles for the trait) are represented by letters (Tt, Aa, BB, dd) Genotypic ratio is reported in the following order - Homozygous Dominant : Heterozygous: Homozygous Recessive Phenotype – the appearance of a trait; what the offspring looks like (Tall : short, curly hair : straight hair) Phenotypic ratio is reported from the Dominant to the Recessive trait showing. The physical appearance of Homozygous Dominant & Heterozygous The physical appearance of : Homozygous Recessive Punnett Square – device showing probability of traits Parental alleles -gametes (genotype) goes on the outside of the box H h H HH Hh h Hh hh Dominant (capital letters) trait will appear (covers any recessive traits) Recessive (lower case letters) – trait is masked or covered by the dominant. Recessive traits only show up it it is homozygous recessive (lower case) 1 : 2 : 1 Genotype ratio 3 : 1 Phenotype ratio show trait : don’t show trait HD: HE : HR Homozygous Dominant - both capital letters/dominant for genotype (TT , AA, BB) Heterozygous - One letter is capital/dominant & one is small/recessive (Tt, Aa, Bb) Homozygous Recessive – both letters are small/recessive (tt, aa, bb) Pedigrees – graphic organizer showing family & trait occurrence by genotype (Some pedigrees show only phenotypes) Males Females Homozygous for trait heterozygous for trait Genetic Conditions Dominant genes Polydactyly Cataracts Scoliosis Recessive genes Albinism PKU Cystic Fibrosis Polygenic traits skin color hair color height Multiple alleles Blood types Extra Chromosome Downs Syndrome Missing Chromosome Turner’s Syndrome Sex-influenced baldness Sex-linked Color blind Hemophilia Patterns of Inheritance 1. simple dominance (either dominant or recessive) 2. incomplete dominance (blend) 3. codominance (both show) 4. multiple alleles (more than one allele represents a trait - blood types) 5. sex-linked (carried on X – more common in males) 6. polygenic (more than one gene represents a trait)